Ever had a homemade soap that doesn’t smell the same anymore? Or maybe has spots on it? This usually is a sign of soap gone bad. This might sound crazy to some, but soaps (especially homemade) do have a shelflife, but the question is, how long?
A bar of handmade soap once used typically lasts between 20-30 showers. If stored correctly it can have an active shelflife of around one year up to two years in some cases. This is highly dependent on the natural ingredients used when making the soap and also how it’s stored.
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Commercial soaps have a lot of advantages compared to homemade ones. Not only do they have a longer shelf life, but they are also manufactured in large quantities, and the ingredients used are inexpensive.
Handmade soaps, on the other hand, you would need to use them within a few months, and if you want to have a decent one, you might need to buy oils that are more on the expensive side. Having said that, commercial soaps are, in most cases, not friendly to your skin.
They are made with ingredients that are chemicals based, and also many of the soaps have their glycerin removed (manufacturers make more profit by selling it separately), which again doesn’t really help your skin in the long run. But homemade soaps, on the other hand, are much better for your skin because they are made out of natural products, and also, their glycerin is never removed.
So in the end, probably the most significant disadvantage of homemade soap would be its shelf life.
The logic question is, is it possible to prolong the shelf life? Is there a way to use your homemade soaps even after one or two years?
How long does soap last?
Commercial soap usually lasts 2 to 3 years, where homemade ones will mostly only last one year. The reason for commercial ones lasting longer is simply due to the fact that they have preservatives (formaldehyde) in them, so they can last much longer.
Handmade soaps are different, they are made with oils and lye and typically have no exact shelf life.
Do not confuse curing time with shelf life, curing time for soap is not considered shelf life. It may need 4 to 6 weeks of curing time (or longer depending on what ingredients one uses), this time is not considered shelf life as it is still in the saponification process.
Is handmade soap more likely to go bad?
Yes, if you are using natural products such as milk, and fruit purees, they naturally have a much shorter shelf life, and thus the same for your soap. Unfortunately, there is no exact time as this is really tricky to know, the best way to know is to smell them and check if there are any (DOS) spots on them.
Another reason they are more likely to go bad is when they have a very high amount of superfat. This means the percentage of oils that remained unsaponified in the original form is high.
This only happens when a specific type of oil is used. For example, if you make a 100% coconut oil soap with a high superfat, it probably will last a very long time, because coconut oil has a long shelf life, to begin with. While if you would use something like avocado oil, it will only be a fraction of it.
Are certain oils more prone to going bad than others?
I already mentioned coconut oil has a long shelf life. But what about others? Which oils last longer and which go bad really fast?
Polyunsaturated oils such as walnuts, soybean, and corn oil go rancid much faster than others. However, monounsaturated oils such as olive and Canola oil do not behave more or less the same way in a soap formula.
Here is a list of monounsaturated oils:
- Olive oil
- Canola oil
- Safflower oil (high oleic)
- Sunflower oil
- Peanut oil and butter
- Sesame oil
Here is a list of Polyunsaturated oils:
- Sunflower seeds
- Flax seeds or flax oil
- Fish, such as salmon, mackerel, herring, albacore tuna, and trout
- Corn oil
- Soybean oil
- Safflower oil
The difference between rancidity and mold and bacteria growth.
Rancidity and mold or bacteria growth separateated issues. Products that contain water are prone to mold and bacteria. To prevent having them, one could use a preservative to help prevent mold and bacteria from growing—however, fresh ingredients such as purees and fresh herbs will still be affected.
This is because they do not go through the saponification process (because you add them after). The same can be said for melt and pour soaps. They are already saponified, so any additive can or will grow mold eventually, and if these additives are fresh, it goes even faster!
We already discussed oils going rancid earlier. But that was just one type; there are many types of rancidity. Oxidative rancidity or microbial rancidity, and hydrolytic rancidity are equally common. I will not detail each of them, but the main thing to remember is that they all lead to the same at the end.
Ingredients that are rancid mostly smell bad or have spots with different colors and might even lose effectiveness. This is a sign that the component used has passed its shelf life. So when you use a type of oil and are planning on stocking on soaps, using one that has a long-life shelf is probably the better option.
Rancidity occurs when it’s past the shelflife; however, mold can occur at any point.
What happens when soap goes bad?
Depending on what has happened, it can or else have mold, or it will get rancid. So it might smell bad or have spots on them. It might also have big dark areas, which usually indicate mold. One may be able to remove the area affected by mold and use the rest of the soap, but this is not recommended.
If it has gone rancid, you may be able to use it, but it may not have the same effect anymore. If it has mold on it, you might end up with a burning sensation, but this depends on the ingredients used.
Just don’t forget that if fresh ingredients were used when making this soap and they have gone bad, it is the same as if you are putting those ingredients on your skin without the soap. Would you do it?
How to prolonge homemade soap life?
The easy but not recommended way is to use synthetic stabilizers or preservatives to prolong shelf life. However, as discussed earlier, this will lead to skin irritation, so you are basically doing the same as big manufacturers.
Homemade natural soaps need exposure to air; this promotes hardening and finally contributes to longer-lasting quality. It would be best if you always left soaps unwrapped in their boxes or with breathable materials. If it’s wrapped tightly, it will cause humid conditions, which prevents moisture from evaporating. Soaps need to be in a dry and cool place, away from excessive heat and humidity.
The following does also help:
Use natural antioxidants, such as rosemary oil extract, to help prolong the shelf life.
Package them in breathable packaging.
If your soaps are scented, like Lavender Rosemary, you can put them in a muslin soap bag or just simply wrap them in a piece of cloth. Afterward, put them in a closet or dresser drawer to give fragrance to your clothes while waiting to be used.
But, don’t forget that the main cause of short shelf life is always the components used to make the soap. If you know more or less the shelf life of the oil or whichever fresh additive you have used. You would be able to tell when the soap will expire.
How to store homemade soap?
Having your soaps stored correctly will prolong their shelf life and will get your soap to be firmer in texture, and finally, it helps you battle molds or soap rancidity.
They need to have room to breathe so the moisture can escape, and you can let it cure correctly for as long it’s needed. If you do not, you may end up with orange spots on them, which indicates that it has exceeded their shelf life because of the bad condition they were stored in.
Here are the following points that can help you store the soaps correctly:
- The place needs to be well ventilated.
- Use an open rack to cure your soaps so air can flow through it. In case you choose to go with a rack, make sure the metal is coated or else metal rust will make your soap to go rancid.
- Even after the soap has cured for the recommended amount of time, it still should have airflow. Many soap makers have two racks, one for curing and another for cured soaps.
- If you package your soaps before they are fully cured, you will get mold on it, and the reason for this is because you did not give enough time for the moisture to escape.
- It would be best if you also tried to store your ingredients and oils to store in a fridge or freezer even so that you can prolong its shelf life. Recommended is to store them in a dark and cool, dry place.
Here is a video below, with some storing tips.
It’s important to keep in mind that the shelf life of ingredients is an estimate. The environment and how products are stored will also affect the shelf life of the item. Oils and other ingredients with a short shelf life can be stored in the fridge or freezer to help them last longer.
I always recommend storing your products in a dark, cool, and dry place to help them last as long as possible. This is particularly true for bath bombs that can begin to fizz prematurely if exposed to humidity, or lotion can separate when exposed to high temperatures.
Click here to learn more about properly storing your products. Ingredients also have natural variation, and the shelf life may slightly depend on the source.